Carburetor



Oct. 30, 1934. c. H. WYNNE ET AL CARBURETOR Filed April 6, 1935 INVENTORS. Char/e5 H. L. Wynne BY 6n s Patented Oct. 30, 1934 Q l UNI'TED'STATES PATENT OFFICE I CARBURETOR Charles Horace Lionel Wynne, Ernest Walter Knott, and Andrew Craig Miller, Tyseley, Bir- -mingham, England, assignors to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application April 6, 1933, Serial No. 664,694

In Great Britain June 4, 1932 1 3 Claims. (Cl. 261-41) This invention relates to improvements in carthrottle in such a manner that the throttle can buretors for internal combustion engines emonly be opened to a limited extent when the valve ploying liquid fuel. is open so that over-driving of the engine when The object of our invention is to provide an cold will be prevented.

5 improved carburetor having means for supplying Two practical forms of our invention are il- 60 to the engine when starting from cold a rela- .lustrated by way of example in the accompanying tively rich and uniform mixture of fuel and air drawing in which: which is supplied independently of the mixture Figure 1 is a, diagrammatic section of a form of supplied from the main jet or jets and controlled our starting device applicable to any type of carby the throttle. Starting is eifected with the buretor, the valve being shown in the closed 65 throttle closed and the use of the auxiliary mixposition. ture-supplying means is, to a. certain extent, Figure 2 is a similar section showing the valve equivalent to opening the throttle slightly and in the open position. will keep the engine running faster than the Figure 3 is a section showing a form of the normal idling speed, but the mixture supplied by device applicable to a carburetor of the type de- 70 the auxiliary means is richer than the mixture scribed in the specification of British patent apnormally supplied by the carburetor with the plication No. 22,002 of 1931. throttle closed and is always uniform so that Figure 4 is a. diagrammatic showing of the starting is greatly facilitated. carburetor illustrated in Figure 3. v According to our invention a rotatable or In the construction illustrated in Figures 1 and 75 otherwise movable valve member mounted in the 2 a is a cylindrical chamber formed in any concarburetor body controls inter-communicating venient part of the carburetor body. Working passages leading respectively to a jet or fuel through a gland nut b which closes the outer end well in the carburetor, to atmosphere, and to an of the chamber is a spindle c carrying a cylindrical opening or openings in the inlet manifold or in piston 01 of any suitable material which is a good 80 the main mixture supply tube on the engine side sliding fit in the cylinder. -A passage e leads from of the throttle. When starting the engine from one side of the cylinder to an opening I in the wall cold the valve member is placed in such a posiof the main mixture supply tube a on the engine tion that all three passages are in communicaside of the throttle valve 11., and a passage 7' leads :0 tion with each other and the suction of the enfrom the opposite side of the cylinder into a pas- 85 gine draws fuel from the jet or well, the fuel sage k. One end of this passagekopens to atmosbeing broken up and mixed with air as it passes phere through a calibrated orifice Z and the other through the valve. The rate of feed of the fuel end of the passage leads into the float chamber m is conveniently controlled by a metering jet or or other fuel reservoir, a restriction or jet n being restriction in the fuel passage on the supply 'side located in the passage to control the rate of flow 90 of the .valve and the air inlet passage is so dimenof the fuel. sioned as to give with the fuel the necessary rich For starting the engine the throttle valve is mixture for starting, the total rate of supply of closed and the piston is moved into the position the mixture being preferably such as to permit shown in Figure 2'in which the passages e and y 40 the engine to turn over at a reasonably fast idling are uncovered. The suction of the engine then 9 speed for warming up. draws fuel from the fuel reservoir m through the When the engine is sufficiently warm the valve passages k andj and e and at the same time draws is moved into a position to close the passages in through the orifice 1 air which mixes with and and fuel mixture is then drawn from the .carbreaks up the fuel so that the fuel is delivered I buretor in the ordinary way by opening the into the mixture supply tube in the form of a fine 100 throttle. emulsion. or rich mixture. The dimensions of the The valve member may be operated by hand jet n and orifice l are so chosen as to give the from a control on the dash or other convenient necessary rich mixture for easy starting and to point or it may be operated by a thermostat or supply the mixture at such a rate as to permit by combined hand and thermostat controls. For the engine to turn over at a reasonably fast idling Hi5 example a thermostat may be arranged to prespeed.

vent opening -of the valve except when the en- When the engine is sufficiently warm the piston gine is cold and to close the valve automatically valve is moved into the closed position as shown when the engine is sufficiently warm. in Figure l and the throttle valve is opened to sup- The valve may also be interconnected with the ply mixture to the engine in the ordinary way. 3] l,

The piston valve may be operated in any convenient manner as for example by a cable 0 connected to a control on the dash or steering column.

In Figures 3 and 4 our invention is shown as applied to a carburetor of the type described in the specification of British patent application No. 22,002 of 1931, in which a fuel discharge device or jet is formed by an annular chamber 10 between an outer tube 12 to which fuel is fed from a constant-level supply chamber 13 and an inner tube q extending downwardly into the outer tube and open at its upper end to atmosphere, one or more apertures 14 being formed in the wall of the inner tube below the normal fuel level through which air can be drawn by the suction of the engine to mix with the fuel in the annular chamber 10.

In applying the present invention to a carburetor of that type the valve member consists of a cylindrical sleeve p rotatably mounted in the carburetor body in axial alignment with the inner tube q. An axial bore 1' extending through the valve sleeve receives at its inner end the upper end of the inner tube' q which is suitably secured therein, and at the outer end of the valve sleeve which extends outside the carburetor body is a calibrated orifice s through which air is supplied to the inner tube during normal operation of the carburetor. The valve sleeve is also bored transversely as at t at right angles or at any convenient inclination to the axial bore, and in the open or operative position of the valve one end of the transverse bore t is in alignment with a passage u leading to atmosphere and the other end is in alignment with 'a passage 11 leading either through the wall of the main mixture tube or through an external tube to an opening on the engine side of the throttle l6.

Thus when the valve p is in its open position when the throttle is closed, the engine is in communication through the valve with the inner tube q which extends down into the fuel in the outer jet tube 12 and the engine draws fuel in from the inner tube q through the valve sleeve 12 and passage 1). At the same time air is drawn in with the fuel from the passageu by means of the transverse bore tin the valve sleeve and mixes with the fuel as the fuel passes from the axial bore 1 into the transverse bore t so that the fuel is aerated and broken up.

The rate of feed of the fuel is conveniently con trolled by a metering jet or restriction to in the axial bore 1' in the valve sleeve between the transverse bore and the upper end of the inner tube and the air supply may be controlled by a restric tion y in the passage u. 7

When the engine is sufllciently warm the valve sleeve is rotated through a right angle so that the transverse bore q iscut off from the engine and from atmosphere but air can pass through the axial bore 1" from the orifice s at its outer end to the inner tube to form an air-bleed for the fuel in the annular main jet 10.

To prevent over-driving of the engine when cold the valve sleeve p may be interconnected with the throttle in such a way as tolimit the extent to which the throttle can be opened while the starting device is in use. In one convenient arrangement an arm on the valve sleeve 17 is connected by a slotted link to a lever keyed on the throttle spindle. The throttle control is connected to a second lever rotatably mounted on the throttle spindle and the two levers are connected by a tension spring and have engaging stops or lugs so arranged that when the valve sleeve is in the open or starting position the throttle can only be opened through, say, one fourth of its range although the spring connection between the levers permits the full normal movement of the accelerator pedal. When the engine has warmed up sufficiently the starting device is returned to its inoperative position by the hand control or thermostat and the throttle can then be opened to any desired extent, the spring connecting the two levers being sufficiently strong to carry the first lever and throttle spindle round with the second lever when the stop formed by the link from the starting device is disengaged.

We-claim:

1. In a carburetor for an internal combustion engine, a main fuel nozzle comprising an inclined tube extending upwardly and inwardly into the carbureting passage and a tube of smaller cross section having one end projecting into said inclined tube and spaced therefrom to form a fuel discharge orifice, a conduit connecting the other end of the smaller tube to atmosphere, a manually operable valve controlling said conduit, and a second conduit connecting said smaller tube to the carburetor posterior to the throttle.

2. In a carburetor for an internal combustion engine, a main fuel nozzle comprising an inclined fuel tube extending upwardly and inwardly into the carbureting passage and an air-bleed tube having one end projecting into said inclined tube and spaced therefrom to form a fuel discharge orifice, a conduit connecting the other end of the air bleed tube to atmosphere, a rotatable valve controlling said conduit, an orifice connecting said other end of the air bleed tube to atmosphere independently of the first mentioned conduit, and a fuel conduit connecting said other end of the air bleed tube to the carburetor posterior to the throttle.

3. In a carburetor for an internal combustion engine, an inclined fuel tube extending upwardly and inwardly into the carbureting passage, a second tube having one end projecting into said inclined tube and spaced therefrom to form a fuel discharge orifice, a chamber at the other end of said second tube, a constantly open calibrated air inlet into said chamber, a second air inlet into said chamber, an outlet from the chamber to the carbureting passage posterior to the throttle, and a rotary valve manually operable to simultaneously close said second air inlet and said outlet.

CHARLES HORACE LIONEL WYNNE. ERNEST WALTER KNOTT. ANDREW CRAIG MILLER. 

